In cases of lower urinary tract disorders, the bladder has been extensively studied, and the urethra remains largely ignored. Thus, the long-term objective of this research project is to understand how the functionality and tissue properties of the female rat urethra are affected by SUI and SCI. Since longitudinally and circumferentially oriented smooth and striated muscle comprise the urethra, the current ex vivo urethral testing system will be modified so that longitudinal tension can be measured simultaneously with the circumferential measurements. The animal model for stress urinary incontinence will involve birth simulation by vaginally distending a rat with a balloon catheter, and the spinal cord injury will be achieved by transection of the spinal cord (segments T-8 to T-10). Urethras will be excised and tied onto tees of the modified ex vivo physiological system where they will be assessed for biomechanical properties (e.g. incremental compliance, elastic modulus and beta stiffness) and smooth and striated muscle function. This data will be correlated to histological findings (e.g. smooth and striated muscle quantification, collagen and elastin quantification, and nerve damage assessments), and all pathologic data will be compared to healthy controls. [unreadable] [unreadable]